Mucus is a substance produced by the body to lubricate the tissues. It protects the gastrointestinal cavity, lungs, sinuses, and throat. Mucus present in the lining of the colon and small intestine protects the gut from stomach acids and irritation.
Aside from giving protection, mucus also lubricates the food as it goes down the digestive tract, greatly reducing the risk of blockage and ensuring proper digestion. Without mucus, food particles will stick together and clump like clay that makes it difficult to pass through the esophagus and intestines.
In itself, mucus is an inert substance consisting of water and proteins. It is produced by goblet cells found in several organs in the digestive system such as esophagus, stomach, and the intestines.
Although often normal, mucus in the stool is sometimes a feature of certain conditions that affects the digestive system. These conditions may cause increased mucus production, or speeds up the passage of food throughout the digestive tract that leaves mucus largely intact in the stool.
Because of its importance, the digestive system produces mucus generously and continuously, producing enough to renew the entire digestive tract in a matter of hours. The digestive tract actually produces two kinds of mucus; a denser, stickier mucus that provides an inner layer, and an outer layer of unattached and less dense mucus. The inner layer of mucus protects the lining of the digestive tract and makes it slippery, while the outer layer mixes with the swallowed food that lubricates it down to the smallest particle.
Aside from lubricating the digestive tract, mucus also other important purposes. The good bacteria in the colon, which is responsible for digesting dietary fiber, anchors to the outer layer of mucus so it sticks to food particles. Meanwhile, the inner layer of mucus is impermeable to most bacteria, protecting the digestive lining from infection as it does its work. At times, some bacteria still manage to penetrate this inner layer. If this occurs, the immune system components are activated that cause inflammation. Despite the apparent shortcomings of the inner mucus layer, it does a good purpose of preventing your immune system from reacting to every bacteria present in food that are often harmless.
Mucus sticks to the stool until it is removed from the body. Because it is produced continuously by the digestive tract, the presence of small quantities of mucus in the stool, or having it very occasionally, is considered normal and should not be a cause for alarm.
Mucus in stool is considered a sign or a symptom, rather than a distinct medical condition. Note that mucus in stool is very different from mucus discharge in the anus, which is the discharge of mucus with little or no stool.
Some of the symptoms accompanying mucus in stool which indicate a more serious underlying problem include:
Blood in mucus is often a result of damage or inflammation in the lining of the digestive tract. Passing out reddish or pinkish mucus may mean bleeding from inside the large intestine where blood has little time to clot. Passing out dark or brownish mucus is indicative of bleeding in the small intestine, stomach, or in the esophagus.
The excess amount of mucus in stool can be seen right away, or may be seen in stool examination. It is often caused by diarrhea, as too rapid bowel movements causes mucus to accumulate in the stool. Another common cause is infection or inflammation in the digestive tract. Several disorders in the digestive tract have stool in mucus as a symptom.
Mucus present in the intestine protects the gut from residues of food and also pathogens in the intestine. The presence of increased quantity of mucus in stool may indicate a gastrointestinal disease.
The mucus layer in the intestine is broken by the inflammatory process and this causes mucus to be excreted in the stool.
The inflammatory conditions that cause excretion of mucus in stool include:
Dehydration and constipation may also produce excess mucus in stool. Diagnosis of the underlying cause of the problem is very important in the prompt and successful treatment of the condition.
Physical examination and blood tests are important in understanding the basic health of the patient and the underlying cause of excess mucus in stool.
For additional information for confirmation tests like blood tests, stool test, urine analysis, colonoscopy, endoscopy, imaging studies and sweat test are recommended.
In most of the cases, diagnosis of the underlying cause is easily identified. In some cases, it is hard to identify the actual cause of the condition.
Lifestyle modifications are suggested for alleviating the symptom. This includes having plenty of fluids, eating food rich in probiotics, having more of anti-inflammatory foods, and having a balanced diet.
For chronic conditions like IBS, cystic fibrosis, Crohn’s disease, ulcerative colitis, medications are suggested. For conditions like anal fissures and anal fistulas, surgery may be needed.
Thus, a combination of medications, lifestyle modifications, and other treatment may be useful in the successful treatment of the condition.
Maintaining healthy bacteria in the intestine is very important in having intact mucosal barriers. In some cases, mucus levels may change after a course of antibiotics. It is important to seek medical attention when the mucus level does not resolve within a few days.
Symptoms and conditions that make them worse or improve should be tracked carefully. This will help in easy identification and prompt treatment of the condition. The outlook of treatment is good in most of the cases.
The presence of excess mucus in the stool may be an indication of an intestinal issue. Studies show that inflammatory conditions break the mucus layer and lead to its excretion in the stool. Breakdown of mucus layer increases the chance of pathogenic invasion in the body.
This increases the risk of infections and illness. Dehydration and constipation cause excess excretion of mucus in the stool and the changes may occur all on a sudden. But in these cases, symptoms resolve without any specific treatment.
Mucus in stool is often normal and may occur occasionally. It may also occur in an occasional diarrhea or stomach upset.
However, frequent or excessive mucus can be a sign of a health problem in the digestive system. It is often a feature of conditions that cause inflammation or infection in the digestive tract. There is evidence that inflammation in the intestines does cause increased mucus production, just like when you expel phlegm or snot when you have colds, sore throat, or flu. Note that your airways also have their own mucus glands too.
In some cases, mucus in stool might be caused by the presence of tumors, polyps, or cancerous growths in the intestine. Growths in the intestine may either increase mucus production or disturb the passage of food. Another frequent cause is the presence of parasites in the intestines such as ascaris worm and tapeworms. Parasites are very irritating and cause damage to the inner lining of the intestines.
Many gastrointestinal inflammatory conditions may lead to increased mucus excretion in stool:
The doctor will order a laboratory examination of your stool and assess for other symptoms. Here are those conditions:
Inflammatory bowel disease (IBD) – symptoms of this condition resemble that of IBS, but is more serious of the two. Excess secretion of mucus in the stool is an important symptom of this condition. Crohn’s disease and ulcerative colitis are two inflammatory conditions characterized by the weak immune system and chronic inflammation.
Bacterial infections -- Campylobacter, Salmonella, Shigella, and Yersinia are the common bacterial infections in the gut that lead to food poisoning and other infections. In addition to mucus in stool, it is characterized by diarrhea, abdominal cramps, vomiting, nausea, and fever.
Anal fissures and ulcers – difficulty in bowel movement and persistent diarrhea may lead to a tear in the lining of the lower part of the rectum. This is called as anal fissures and may result in pain during bowel movements and mucus in stools. Ulcers in the anal region, caused by treatments like chemotherapy or radiotherapy leads to loss of mucus barrier, called gastrointestinal mucositis.
Bowel obstruction – obstruction of bowel movement due to conditions like a hernia, tumor or impacted stool cause excretion of mucus in stool. It is associated with other symptoms like abdominal cramps, constipation and bloating.
Other infections – viral and parasitic infections may also lead to the excessive excretion of mucus in stools. Infection by astrovirus, norovirus and rotaviruses are examples of viral infections that lead to this symptom.
Proctitis – proctitis refers to the inflammation of the lining of the rectum. Inflammation of rectum may be caused by sexually transmitted diseases, radiation therapy, and also infection transmitted through foodborne diseases. It is associated with bleeding from the rectum, diarrhea, swelling and abdominal pain.
Food allergies – allergy to nut, lactose or gluten can cause excretion of mucus in stool. This is usually associated with other symptoms like bloating, diarrhea, constipation and rashes.
Hemorrhoids – presence of internal hemorrhoids may result in mucus in stool. It is associated with anal itching, constipation and presence of blood in the stool.
Polyps and cancer – polyps and cancer in the small intestine often have mucus in stool as the only symptom.
Small intestinal bacterial overgrowth – conditions like fructose malabsorption, diabetes, systemic sclerosis, results in bacterial overgrowth. This is characterized by mucus in stools.
Diverticulitis – diverticulitis is a condition characterized by inflammation of pouches in the colon. This also leads to excretion of mucus. Some other conditions that result in this symptoms include pancreatic disease and short bowel syndrome.
Mucus in stool is not a disease or a health condition. In such case, your doctor will do a physical examination, and determine your medical history. A physical exam often consists of examining and palpating your abdomen for any lumps or tenderness. Your doctor will examine your medical history to see any conditions that might explain your symptoms. He or she might also ask for a laboratory examination of your stool called fecalysis. The fecalysis will determine whether your stool do have lots of mucus, as well as check for presence of blood, bile, presence of bacteria or parasites. In some cases, your doctor may order a blood exam as well.
If initial tests show something else, your doctor may ask for an imaging of your abdomen, like an abdominal X-ray, contrast X-ray, or a CT scan to check your digestive tract. In some cases, you may be asked to undergo a colonoscopy, which involves inserting a long, thin, and flexible tube with a light and a camera at one end into your anus to visualize the insides of the digestive tract and check for sources of bleeding or presence of masses.
Addressing the cause often treats mucus in stool. If there is infection, like in the case of dysentery, food poisoning, or salmonella-related diarrhea, your doctor will prescribe antibiotics to kill infective bacteria. In the case of Crohn’s disease or ulcerative colitis, you may be prescribed with medicines that reduce inflammation in the intestines. Some of these medicines include corticosteroids (like prednisolone or hydrocortisone) or aminosalicylates (like sulfasalazine or mesalamine). If the cause is parasitism, which is not uncommon, you may be prescribed with drugs that kill parasites.
Initial tests for the diagnosis of the underlying cause of the symptoms are a physical examination and medical history. Blood tests are also recommended to confirm the suspected cause of the problem.
During the physical examination, the doctor may feel for tenderness or mass in the abdominal region. This is particularly on the left side of the lower abdomen. Tenderness in this region may suggest ulcerative colitis or irritable bowel syndrome.
The doctor may also carry out a digital rectal examination to evaluate the condition of the rectum. Additional tests used in the diagnosis include a stool test, urine analysis, imaging studies, and sweat test.
Blood tests are used for the identification of infections. The presence of blood in stool indicates infectious diseases of the intestine. It may also suggest ulcerative colitis. Microscopic examination of stool helps in the identification of parasites, while culture aids in the identification of causative bacteria.
Some other tests used in the diagnosis of the cause are:
Endoscopy – in this procedure, a small tube with a camera, in the end, is inserted through the mouth to visualize stomach and upper part of the small intestine. This diagnostic procedure is also used to collect biopsy samples from these regions.
Flexible sigmoidoscopy – in this imaging device a small camera is used to visualize the structures in lower part of the bowel.
Colonoscopy – as the name indicates this procedure helps to obtain live images of the colon. It is also used to collect biopsy samples from these regions.
Enteroscopy – in this procedure a small capsule, which contains a camera, is swallowed. This provides images of the digestive system as the capsule passes through it.
Barium enema – also known as barium x-ray, this contrast dye helps to obtain images of the digestive system.
Treatment is based on the diagnosis of the underlying condition.
In most of the cases, lifestyle modifications help in resolving the condition, this includes:
Keeping the body well hydrated
Including more of probiotics in food. One may also look for supplements that contain probiotics.
Avoiding spicy and acidic food.
Having a healthy and balanced diet with more of fiber and carbohydrates
Chronic conditions like IBS, cystic fibrosis, Crohn’s disease and ulcerative colitis are treated with prescription medications. Surgical procedures are recommended for resolving anal fistulas and anal fissures.
These conditions may need a combination of lifestyle modifications, prescription medications, and surgery. Antibiotics are recommended for bacterial infections that result in this symptom. Symptoms of this condition heal better with adequate rest and hydration.
Under normal conditions, the mucus levels in stool vary from time to time. The normal mucosal barrier of the body is maintained by the natural flora of the intestine.
People who had a course of antibiotics tend to lose these beneficial organisms, leading to loss of mucosal barrier. This may affect the excretion of mucus in stools. If the condition does not resolve on its own within few days, one may have to seek medical attention.
One should keep track of the other symptoms, its onset, duration, intensity, and conditions that make it worse or better. Medications and appropriate lifestyle modifications are important in controlling these symptoms.
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